From patchwork Mon May 10 16:59:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 12248957 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73668C43460 for ; Mon, 10 May 2021 17:28:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 525A86157F for ; Mon, 10 May 2021 17:28:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232944AbhEJR3Q (ORCPT ); Mon, 10 May 2021 13:29:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:53290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232807AbhEJR24 (ORCPT ); Mon, 10 May 2021 13:28:56 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7C39C61554; Mon, 10 May 2021 17:27:51 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lg9Gp-000Uqg-UY; Mon, 10 May 2021 18:00:40 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Jintack Lim , Haibo Xu , James Morse , Suzuki K Poulose , Alexandru Elisei , kernel-team@android.com Subject: [PATCH v4 62/66] KVM: arm64: nv: Sync nested timer state with ARMv8.4 Date: Mon, 10 May 2021 17:59:16 +0100 Message-Id: <20210510165920.1913477-63-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210510165920.1913477-1-maz@kernel.org> References: <20210510165920.1913477-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, andre.przywara@arm.com, christoffer.dall@arm.com, jintack@cs.columbia.edu, haibo.xu@linaro.org, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Christoffer Dall Emulating the ARMv8.4-NV timers is a bit odd, as the timers can be reconfigured behind our back without the hypervisor even noticing. In the VHE case, that's an actual regression in the architecture... Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/kvm/arch_timer.c | 37 ++++++++++++++++++++++++++++++++++++ arch/arm64/kvm/arm.c | 3 +++ include/kvm/arm_arch_timer.h | 1 + 3 files changed, 41 insertions(+) diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 8a4fce4ec7d8..c0064168b38d 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -778,6 +778,43 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) set_cntvoff(0); } +void kvm_timer_sync_nested(struct kvm_vcpu *vcpu) +{ + if (!is_hyp_ctxt(vcpu)) + return; + + /* + * Guest hypervisors using ARMv8.4 enhanced nested virt support have + * their EL1 timer register accesses redirected to the VNCR page. + */ + if (!vcpu_el2_e2h_is_set(vcpu)) { + /* + * For a non-VHE guest hypervisor, we update the hardware + * timer registers with the latest value written by the guest + * to the VNCR page and let the hardware take care of the + * rest. + */ + write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTV_CTL_EL0), SYS_CNTV_CTL); + write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTV_CVAL_EL0), SYS_CNTV_CVAL); + write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTP_CTL_EL0), SYS_CNTP_CTL); + write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTP_CVAL_EL0), SYS_CNTP_CVAL); + } else { + /* + * For a VHE guest hypervisor, the emulated state (which + * is stored in the VNCR page) could have been updated behind + * our back, and we must reset the emulation of the timers. + */ + + struct timer_map map; + get_timer_map(vcpu, &map); + + soft_timer_cancel(&map.emul_vtimer->hrtimer); + soft_timer_cancel(&map.emul_ptimer->hrtimer); + timer_emulate(map.emul_vtimer); + timer_emulate(map.emul_ptimer); + } +} + /* * With a userspace irqchip we have to check if the guest de-asserted the * timer and if so, unmask the timer irq signal on the host interrupt diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 2e4d74caa114..4d9b3a9e21fd 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -858,6 +858,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) if (static_branch_unlikely(&userspace_irqchip_in_use)) kvm_timer_sync_user(vcpu); + if (enhanced_nested_virt_in_use(vcpu)) + kvm_timer_sync_nested(vcpu); + kvm_arch_vcpu_ctxsync_fp(vcpu); /* diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 063f613fbc7e..2e20916e9025 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -68,6 +68,7 @@ int kvm_timer_hyp_init(bool); int kvm_timer_enable(struct kvm_vcpu *vcpu); int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu); void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu); +void kvm_timer_sync_nested(struct kvm_vcpu *vcpu); void kvm_timer_sync_user(struct kvm_vcpu *vcpu); bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu); void kvm_timer_update_run(struct kvm_vcpu *vcpu);